The problem with calculating calorie needs

written by Philip Stefanov  |  OCTOBER 11, 2022

Let’s calculate a hypothetical person’s total daily energy expenditure (TDEE) using this calculator. According to it, a 26-year-old man who weighs 90 kilograms (198 lbs), is 190 cm tall (6’3”), and is moderately active should eat around 3,040 calories each day.

Now, let’s plug the same information into a second calculator. The estimated TDEE is 2,875 calories.

Okay, let’s try a third calculator. What? 2380 calories?

So, between three calculators, the recommended energy intake can vary by as much as 660 calories. But what gives?

The Problem With Calorie Calculators

Calorie calculators are based on formulas like the Harris-Benedict equation. We also have the Mifflin St Jeor equation, the Katch–McArdle formula, and other options.

Each formula takes specific variables into account when determining your calorie needs. As such, the various methods yield unique results.

Unfortunately, even small variability is enough to confuse and frustrate people. For instance, if you’re new to fitness and want to lose weight, it can be challenging to figure out how many calories you should eat. One calculator claims 1,500 calories; another recommends 2,000, and a third suggests 1,750.

The Mistake We’ve All Made

The mistake we’ve all made when calculating our calories is obsessing over the theoretical ‘best’ answer. Instead of getting started, we jump from one calculator to the next, seeking the one that will deliver the most accurate answer.

Here’s the truth:

All calorie calculators and formulas are nothing more than estimates because numerous factors go into your unique calorie needs. There might be a formula that will work better for you, but you can’t be sure, and there is no point in wasting your time instead of taking action.

But What Can You Do About It?

Pick one method for calculating your calories and get started. As mentioned, all the methods provide an estimate for your calorie needs, so there is no point in spending too much time to find the perfect answer.

Once you have your TDEE value, adjust your calorie goals based on your goals and start tracking your weight, circumference measurements, and visual appearance (progress photos).

You might get lucky and calculate your calories accurately, but that’s usually not the case. Most people calculate their calories and adjust their intake based on the feedback they get from their bodies.

For example, you might calculate your starting fat loss calories at 2,500. But, if you fail to lose weight over two to three weeks, you will likely have to drop the intake by 100 to 200 and see if that creates the necessary deficit to move the needle.

Similarly, you could calculate your calories for bulking, but if you fail to gain weight over several weeks, you will have to adjust your intake.

2 Examples of Calorie Adjustments

Fat Loss

Estimated TDEE: 2,850 calories
Calories for fat loss (0.5 to 0.7 percent/week): 2,350-2,450

Week 1 average: 187.4 lbs
Week 2 average: 186.0 lbs
Week 3 average: 184.1 lbs
Week 4 average: 182.3 lbs

As you can see, the initial calculation is off for some reason. Maybe the person is more active or has a highly adaptive metabolism.

In any case, his weight loss is much quicker than anticipated, so it would be best to bump his intake by 150 to 200 and track for a few more weeks. The goal is to reach a calorie intake that leads to around 0.8 to 1.2 lbs of weekly weight loss.

Muscle Gain

Estimated TDEE: 3,050 calories
Calories for steady weight gain (1-1.25 percent gain/month): 3,200

Week 1 average: 190.3 lbs
Week 2 average: 191.4 lbs
Week 3 average: 192.2 lbs
Week 4 average: 193.0 lbs

Here we can see that weight gain is much faster than desired, and eating that many calories would result in too much fat gain. So, we scale it back by about 200 calories and track for some time to see if the rate of weight gain slows down to the desired speed.

Is the process tedious? A bit. Can it be challenging to tell if you’re doing well? Yes. But making an effort and adjusting your intake will lead to steadier weight changes that result in superior fat loss and muscle gain.

Thank you for taking the time. Until next week,


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